The first things I would do to an 85 would have nothing to do with breaking into the engine. Upgrading to an 8.8 rear with some nice gears and attached by some nice control arms with nice springs riding on it and nice shocks dampening the bumps. Said rear would have disc brakes attached to it, and the front would get matching springs and a nice brake upgrade, preferably Cobra stuff but at least SN95, using the newer style control arms and all. A set of subframe connectors would be welded in, and a strut tower brace as well. Then I would upgrade to the 86+ style dual exhaust by getting an x pipe and cat back for an 86 GT/87-93 LX 5.0 with the double hump crossmember and associated hangers. Install a good short throw shifter (I like Pro-5.0 but MGW seems to be the favorite around these forums). Then id give the motor a good tune up, accelerator pumps on the carb and advance the timing. Maybe a modest ignition upgrade too. Id have a whole lot of fun with it in this form, THEN i'd tackle taking the engine apart. To me it makes more sense to upgrade the platform on which you will be building before throwing a ton of power at it. But hey, that's just me.